MUNIX and incremental stimulation MUNE in ALS patients and control subjects

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• 作者：Jasna Furtula^a ; Birger Johnsen^a ; Peter Broegger Christensen^b ; Kirsten Pugdahl^a ; Carsten Bisgaard^c ; Mette-Kirstine Christensen^d ; Jens Arentsen^e ; Morten Frydenberg^f ; Anders Fuglsang-Frederiksen^a ; ^{andefugl@rm.dk}
• 关键词：ADM ; abductor digiti minimi muscle ; AH ; abductor hallucis muscle ; ALS ; amyotrophic lateral sclerosis ; ALSFRS-R ; revised amyotrophic lateral sclerosis functional rating scale ; APB ; abductor pollicis brevis muscle ; AUC ; area under curve ; BB ; biceps brachii
• 刊名：Clinical Neurophysiology
• 出版年：2013
• 出版时间：March, 2013
• 年：2013
• 卷：124
• 期：3
• 页码：610-618
• 全文大小：425 K

文摘

Objective

This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS.

Methods

Thirteen ALS patients and 48 control subjects were prospectively investigated - both groups were studied with MUNIX and IS-MUNE applied on the abductor digiti minimi (ADM) muscle. Additional retest was performed on 14 control subjects. Follow-up tests were carried out on 6 patients. The analysis included measures of reproducibility (Intraclass Correlation Coefficient (ICC)) and diagnostic performance (Receiver Operating Characteristic (ROC) analysis).

Results

Test-retest reproducibility was low to moderate for MUNIX and IS-MUNE (ICC = 0.38 and 0.56, respectively). Repeated MUNIX and IS-MUNE measurements on the same subject had a mean percentage difference (MPD) of 20 % and 46 % , respectively (p = 0.039). In the control group, the coefficient of variation was markedly lower for MUNIX than for IS-MUNE (26 % and 44 % , respectively, p < 0.0005). In ALS patients MUNIX had a notably better responsiveness in follow-up than IS-MUNE (percent change per month, 9.4 versus 5.6, p = 0.046). ROC analysis suggested similar diagnostic accuracy of both tests.

Conclusions

MUNIX is a useful MUNE indicator when assessing progression of lower motor neuron affection in ALS. Furthermore, MUNIX displayed lower intrasubject variability, but no evident better diagnostic yield compared with IS-MUNE.

Significance

This study has established comparative assessment of MUNIX and IS-MUNE performance in test-retest setting and as diagnostic tests on a distal muscle in ALS patients.